Bugfixes/improvements for stripe

Bugfixes/improvements for stripe

1) Stripe takes payment amounts in pennies to avoid floating-point
messes.
2) TPAC mod_perl needed to be told to pass along the stripe_token
parameter to the backend.
3) Get exp date, last four from *result* from Stripe, unlike the way we
get these things as input from the client when using other processors
4) Expose Stripe's message to the client in case of decline (and escape
for HTML)

Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>